Exodus 9:8-17

8And Jehovah said unto Moses and unto Aaron, Take to you handfuls of ashes of the furnace, and let Moses sprinkle it toward heaven in the sight of Pharaoh. 9And it shall become small dust over all the land of Egypt, and shall be a boil breaking forth with blains upon man and upon beast, throughout all the land of Egypt. 10And they took ashes of the furnace, and stood before Pharaoh; and Moses sprinkled it up toward heaven; and it became a boil breaking forth with blains upon man and upon beast. 11And the magicians could not stand before Moses because of the boils; for the boils were upon the magicians, and upon all the Egyptians. 12And Jehovah hardened the heart of Pharaoh, and he hearkened not unto them, as Jehovah had spoken unto Moses.

13And Jehovah said unto Moses, Rise up early in the morning, and stand before Pharaoh, and say unto him, Thus saith Jehovah, the God of the Hebrews, Let my people go, that they may serve me. 14For I will this time send all my plagues upon thy heart, and upon thy servants, and upon thy people; that thou mayest know that there is none like me in all the earth. 15For now I had put forth my hand, and smitten thee and thy people with pestilence, and thou hadst been cut off from the earth: 16but in very deed for this cause have I made thee to stand, to show thee my power, and that my name may be declared throughout all the earth. 17As yet exaltest thou thyself against my people, that thou wilt not let them go?